"The Marine Sports Steel-Plated Single Barb Tip features a lightweight design for increased underwater speed and accuracy. Plus, when it hits its target, the single wing tip opens up, and this holds onto your fish for more spearfishing success. Steel plated construction increases its corrosion resistance and strength. Thanks to its 6mm threading, you can simply screw this spearfishing tip to the end of your pole spear (not included) or speargun shaft (not included). The single-barb tip from Marine Sports is best used to spear medium to small fish. Length: 2.5"". Punctures and holds onto fish Increased speed and accuracy Strong, corrosion-resistant steel plating For small to medium-sized fish 6mm threading"